Scale-Dependent Non-Gaussianity as a Generalization of the Local Model

TL;DR

This paper introduces a generalized model of primordial non-Gaussianity with a scale-dependent parameter, analyzing its bispectrum effects and potential for measurement through large-scale structure data.

Contribution

It extends the local non-Gaussianity model by allowing a scale-dependent fNL(k), providing methods to constrain this function from observations.

Findings

Identifies scales where fNL(k) is best constrained.

Calculates the bispectrum for the generalized model.

Estimates overlap with local and equilateral models.

Abstract

We generalize the local model of primordial non-Gaussianity by promoting the parameter fNL to a general scale-dependent function fNL(k). We calculate the resulting bispectrum and the effect on the bias of dark matter halos, and thus the extent to which fNL(k) can be measured from the large-scale structure observations. By calculating the principal components of fNL(k), we identify scales where this form of non-Gaussianity is best constrained and estimate the overlap with previously studied local and equilateral non-Gaussian models.